Develop Reference

Converting string m/dd/yyyy HH:MM:SS to date dd-mm-yyyy in Javascript

I have a string that looks like '1/11/2018 12:00:00 AM' and I want to reformat it to dd-mm-yyyy.
Keep in mind that the month can be double digit sometimes.

You can use libraries like moment.js. Assuming either you do not want to use any external library or can not use it, then you can use following custom method:
function formatDate(dateStr) {
let date = new Date(dateStr);
let day = date.getDate();
let month = date.getMonth() + 1;
let year = date.getFullYear();
return day + '-' + month + '-' + year;
}
console.log(formatDate('1/11/2018 12:00:00 AM'));

You can do somethink like this :
var d = new Date();
var curr_date = d.getDate();
var curr_month = d.getMonth() + 1; //Months are zero based
var curr_year = d.getFullYear();
console.log(curr_date + "-" + curr_month + "-" + curr_year);
However best way is with Moment.js,where you can Parse, Validate, Manipulate, and Display dates in JavaScript.
example:
var date= moment("06/06/2015 11:11:11").format('DD-MMM-YYYY');

function convertDate(oldDate) {
var myDate = new Date(Date.parse(oldDate)); //String -> Timestamp -> Date object
var day = myDate.getDate(); //get day
var month = myDate.getMonth() + 1; //get month
var year = myDate.getFullYear(); //get Year (4 digits)
return pad(day,2) + "-" + pad(month, 2) + "-" + year; //pad is a function for adding leading zeros
}
function pad(num, size) { //function for adding leading zeros
var s = num + "";
while (s.length < size) s = "0" + s;
return s;
}
convertDate("1/11/2018 12:00:00 AM"); //11-01-2018
Demo here

JavaScript date and time formatting,

I have read a lot of thread about the subject, but i'm not much into programming... i've made some tests but never acheive what i wanted.
Here we have a html template we have to modify to suit our needs.
here the code i have to edit:
<p id="DATE"></p>
<script>
var d = new Date();
document.getElementById("DATE").innerHTML = d.toString();
</script>
Its giving me the date OK...but not i the format i want...
the format i want is... DD-MM-YYYY HH:MM
Simple has that :)
Its been a couple of hours and i can't do it... Can anyone help with a code i just can copy/paste in my html file.

As opposed to using an external JavaScript library for a simple task. You should be able to achieve the same with Vanilla js.
Refer to this:
Where can I find documentation on formatting a date in JavaScript?
In short:
var d = new Date();
var curr_date = d.getDate();
var curr_month = d.getMonth() + 1; //Months are zero based
var curr_year = d.getFullYear();
var curr_hour = d.getHours();
var curr_min = d.getMinutes();
console.log(curr_date + "-" + curr_month + "-" + curr_year + " " + curr_hour + ":" + curr_min);
The above snippet should have all the code you need.
For your specific implementation, you will need to do the below:
<script>
var d = new Date();
var curr_date = d.getDate();
var curr_month = d.getMonth() + 1; //Months are zero based
var curr_year = d.getFullYear();
var curr_hour = d.getHours();
var curr_min = d.getMinutes();
var formattedDate = curr_date + "-" + curr_month + "-" + curr_year + " " + curr_hour + ":" + curr_min;
document.getElementById("DATE").innerHTML = formattedDate;
</script>

A function for the format you require is fairly simple. The following will return a string for a provided Date, or the current date if none passed.
function formatDate(date) {
var d = date || new Date();
function z(n){return (n<10?'0':'')+n}
return z(d.getDate()) + '-' +
z(d.getMonth()+1) + '-' +
d.getFullYear() + ' ' +
z(d.getHours()) + ':' +
z(d.getMinutes());
}
document.write(formatDate());
BTW, you can't use the same token for two separate parts. While there is no standard or even consistency for formatting tokens, your format would be more commonly expressed as:
DD-MM-YYYY HH:mm
Which is compatible with moment.js and a few others, though there are many other token sets to represent the same format.

To achieve your goal simply try following codes:
First of all, inside the head tag add the below line of code:
<script src="https://rawgit.com/moment/moment/2.2.1/min/moment.min.js"></script>
Finally, change your existing line of code:
document.getElementById("DATE").innerHTML = moment(d).format('DD-MM-YYYY HH:MM');
Happy coding :)

Date parse format from T with time to mm/dd/yyyy with javascript or jquery

I have the following value:
javascript variable:
"2015-10-14T17:54:19.033"
I want to end up with
mm/dd/yyyy
e.g.
10/14/2015
I was trying to do
var date = month[d.getMonth()] + " " + d.getDay()+ ", " + d.getFullYear();
Here is my Fiddle
http://jsfiddle.net/bthorn/7ptcedt4/
var d = new Date('2015-10-14T17:54:19.033');
var date = d.getMonth().toString() + "/" + d.getDay().toString() + "/" + d.getFullYear().toString();
console.log(date);
Something is NOT right: I am getting
9/3/2015

You can use this:
var date = new Date("2015-10-14T17:54:19.033");
var formatedDateString = (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();
Or use moment.js
var formatedDateString = moment("2015-10-14T17:54:19.033").format('MM/dd/YYYY');
Or may you consider create your own date format function.
PS.: javascript months are 0-indexed, so for the correct month you should use (date.getMonth() + 1)

Combine date and time string into single date with javascript

I have a datepicker returning a date string, and a timepicker returning just a time string.
How should I combine those into a single javascript Date?
I thought I found a solution in Date.js. The examples shows an at( )-method, but I can't find it in the library...

You can configure your date picker to return format like YYYY-mm-dd (or any format that Date.parse supports) and you could build a string in timepicker like:
var dateStringFromDP = '2013-05-16';
$('#timepicker').timepicker().on('changeTime.timepicker', function(e) {
var timeString = e.time.hour + ':' + e.time.minute + ':00';
var dateObj = new Date(datestringFromDP + ' ' + timeString);
});
javascript Date object takes a string as the constructor param

Combine date and time to string like this:
1997-07-16T19:20:15
Then you can parse it like this:
Date.parse('1997-07-16T19:20:15');
You could also use moment.js or something similar.

For plain JavaScript:
combineDateAndTime = function(date, time) {
timeString = time.getHours() + ':' + time.getMinutes() + ':00';
var year = date.getFullYear();
var month = date.getMonth() + 1; // Jan is 0, dec is 11
var day = date.getDate();
var dateString = '' + year + '-' + month + '-' + day;
var combined = new Date(dateString + ' ' + timeString);
return combined;
};

You can concatenate the date and time, and then use moment to get the datetime
const date = '2018-12-24';
const time = '23:59:59';
const dateTime = moment(`${date} ${time}`, 'YYYY-MM-DD HH:mm:ss').format();

Boateng's example fails in cases where time consisted of hours, minutes, days or months that ranged from values 0-9 as getDate(), getMonth() etc... will return 1 digit in these cases and the time string will fail and an invalid date is returned:
function CombineDateAndTime(date, time) {
const mins = ("0"+ time.getMinutes()).slice(-2);
const hours = ("0"+ time.getHours()).slice(-2);
const timeString = hours + ":" + mins + ":00";
const year = date.getFullYear();
const month = ("0" + (date.getMonth() + 1)).slice(-2);
const day = ("0" + date.getDate()).slice(-2);
const dateString = "" + year + "-" + month + "-" + day;
const datec = dateString + "T" + timeString;
return new Date(datec);
};
Unfortunately do not have enough rep to comment

David's example with slight modifications:
function CombineDateAndTime(date, time) {
var timeString = time.getHours() + ':' + time.getMinutes() + ':00';
var ampm = time.getHours() >= 12 ? 'PM' : 'AM';
var year = date.getFullYear();
var month = date.getMonth() + 1; // Jan is 0, dec is 11
var day = date.getDate();
var dateString = '' + year + '-' + month + '-' + day;
var datec = dateString + 'T' + timeString;
var combined = new Date(datec);
return combined;
};

Concate date and time with moment JS which also works on firefox,
let d1 = moment().format('MM/DD/YYYY');
let dateTimeOpen = moment(d1 + ' ' + model.openingTime).format('YYYY-MM-DD HH:mm:ss');
let dateTimeClose = moment(d1 + ' ' + model.closingTime).format('YYYY-MM-DD HH:mm:ss');

const date = "2022-12-27";
const time = "16:26:42";
new Date(`${date}T${time});
output
Date Tue Dec 27 2022 16:26:42 GMT+0100 (Central European Standard Time)

Ajax get Date in dd/mm/yyyy format

var d = new Date();
var today_date = d.getDate() + '/' + month_name[d.getMonth()] + '/' + d.getFullYear();
This is how I am getting a date. It works with a slight problem. For todays date 7th of June 2011 it returns 7/11/2011, what i want it to return is 07/11/2011?
Anyone know how?

Well, you could simply check the length of d.getDate()and if it's 1 then you add a zero at the beginning. But you would like to take a look at format() to format your dates?

Like so:
("0"+1).slice(-2); // returns 01
("0"+10).slice(-2); // returns 10
Complete example:
var d = new Date(2011,1,1); // 1-Feb-2011
var today_date =
("0" + d.getDate()).slice(-2) + "/" +
("0" + (d.getMonth() + 1)).slice(-2) + "/" +
d.getFullYear();
// 01/02/2011

Try this (http://blog.stevenlevithan.com/archives/date-time-format):
var d = new Date();
d.format("dd/mm/yyyy");

Try this, this is more understandable.:
var currentTime = new Date();
var day = currentTime.getDate();
var month = currentTime.getMonth() + 1;
var year = currentTime.getFullYear();
if (day < 10){
day = "0" + day;
}
if (month < 10){
month = "0" + month;
}
var today_date = day + "/" + month + "/" + year;
document.write(today_date.toString());
And result is :
07/05/2011